International Agency for Research on Cancer (IARC) - Summaries & Evaluations

METHYL IODIDE

VOL.: 41 (1986) (p. 213)

CAS No.: 74-88-4Chem. Abstr. Name: Iodomethane

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Methyl iodide is formed principally in the oceans. Smaller amounts are
produced industrially for use as a chemical intermediate. Exposures
occur from occupational use and from ubiquitous low-level exposure in
ambient air and in water.

5.2 Experimental data

Methyl iodide was tested for carcinogenicity in one experiment in rats
by subcutaneous administration and in a screening test for lung
adenomas in strain A mice by intraperitoneal injection. It induced
local sarcomas in rats after single or repeated subcutaneous
injections; a marginally increased incidence of lung tumours was
observed in mice.

No data were available to evaluate the reproductive effects or
prenatal toxicity of methyl iodide to experimental animals.

Methyl iodide induces DNA damage and is mutagenic to bacteria in the
presence or absence of an exogenous metabolic system. It induces
mitotic recombination in yeast and mutations in cultured mammalian
cells. It induces transformation in Syrian hamster embryo cells but
not in C3H 10T1/2 cells.

5.3 Human data

No data were available to evaluate the reproductive effects or
prenatal toxicity of methyl iodide to humans.

No case report or epidemiological study of the carcinogenicity of
methyl iodide to humans was available to the Working Group.

4.4 Evaluation

There is limited evidence for the carcinogenicity of methyl iodide
to experimental animals.

No evaluation could be made of the carcinogenicity of methyl iodide to
humans.